The field of the invention relates to vehicle control, wherein the vehicle is powered by an internal combustion engine having a compression device.
To obtain improved engine power to displacement for improved vehicle driveability, turbo charging, or supercharging has been used. In this system, engine performance is increased by compressing air entering and engine intake manifold, thereby forcing more air into an engine cylinder. The engine then produces increased engine torque. Such an approach is advantageous in improving vehicle fuel economy by reducing engine size and weight while obtaining equal maximum engine performance.
The inventors herein have found a disadvantage with the above approach. In particular, the phenomena known as xe2x80x9cturbo lagxe2x80x9d degrades drive performance during transient driver commands. For example, at lower engine speeds and low engine torques, when a driver requests a rapid increase in torque, there is a delay since the turbo charger first builds up speed and the engine manifold then builds pressure. These combined delays produce xe2x80x9cturbo lagxe2x80x9d.
An object of the present invention is to provide an engine control method capable of reducing delayed response from an engine coupled to a compression device.
The above object is achieved and disadvantages of prior approaches overcome by a method for controlling an engine having at least one cylinder, the engine also having an intake manifold and an outlet control device for controlling flow from the intake manifold into the cylinder, the intake manifold coupled to a compression device for compressing the flow into the intake manifold, comprising: generating an operator command; and controlling flow into the cylinder by changing the outlet control device to control flow into the cylinder based on said operator command.
By using the outlet control device to rapidly adjust flow into the cylinder faster than possible by using the inlet control device, it is possible to compensate for compression device response delays. In other words, the rapid increase in cylinder charge can mask the compression device delay, thereby giving good drive feel and the benefits of a compression device.
An advantage of the above aspect of the invention is that improved fuel economy is achieved.
Other objects, features and advantages of the present invention will be readily appreciated by the reader of this specification.